1 /* 2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "opto/arraycopynode.hpp" 26 #include "opto/graphKit.hpp" 27 #include "opto/idealKit.hpp" 28 #include "gc/shared/c2/modRefBarrierSetC2.hpp" 29 30 Node* ModRefBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const { 31 DecoratorSet decorators = access.decorators(); 32 33 Node* adr = access.addr().node(); 34 35 bool is_array = (decorators & IS_ARRAY) != 0; 36 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; 37 bool in_heap = (decorators & IN_HEAP) != 0; 38 bool use_precise = is_array || anonymous; 39 bool tightly_coupled_alloc = (decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0; 40 41 if (!access.is_oop() || tightly_coupled_alloc || (!in_heap && !anonymous)) { 42 return BarrierSetC2::store_at_resolved(access, val); 43 } 44 45 assert(access.is_parse_access(), "entry not supported at optimization time"); 46 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access); 47 48 Node* store = BarrierSetC2::store_at_resolved(access, val); 49 post_barrier(parse_access.kit(), access.base(), adr, val.node(), use_precise); 50 51 return store; 52 } 53 54 Node* ModRefBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 55 Node* new_val, const Type* value_type) const { 56 if (!access.is_oop()) { 57 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type); 58 } 59 60 Node* result = BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type); 61 62 post_barrier(access.kit(), access.base(), access.addr().node(), new_val, true); 63 64 return result; 65 } 66 67 Node* ModRefBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 68 Node* new_val, const Type* value_type) const { 69 GraphKit* kit = access.kit(); 70 71 if (!access.is_oop()) { 72 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); 73 } 74 75 Node* load_store = BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); 76 77 // Emit the post barrier only when the actual store happened. This makes sense 78 // to check only for LS_cmp_* that can fail to set the value. 79 // LS_cmp_exchange does not produce any branches by default, so there is no 80 // boolean result to piggyback on. TODO: When we merge CompareAndSwap with 81 // CompareAndExchange and move branches here, it would make sense to conditionalize 82 // post_barriers for LS_cmp_exchange as well. 83 // 84 // CAS success path is marked more likely since we anticipate this is a performance 85 // critical path, while CAS failure path can use the penalty for going through unlikely 86 // path as backoff. Which is still better than doing a store barrier there. 87 IdealKit ideal(kit); 88 ideal.if_then(load_store, BoolTest::ne, ideal.ConI(0), PROB_STATIC_FREQUENT); { 89 kit->sync_kit(ideal); 90 post_barrier(kit, access.base(), access.addr().node(), new_val, true); 91 ideal.sync_kit(kit); 92 } ideal.end_if(); 93 kit->final_sync(ideal); 94 95 return load_store; 96 } 97 98 Node* ModRefBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const { 99 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, new_val, value_type); 100 if (!access.is_oop()) { 101 return result; 102 } 103 104 post_barrier(access.kit(), access.base(), access.addr().node(), new_val, true); 105 106 return result; 107 }